Missouri Gov. Eric Greitens appears to be reinforcing his anti-union image, inviting Wisconsin Gov. Scott Walker — who also has built a reputation for taking on unions — to a rally Tuesday, where Greitens signed a bill outlawing a longstanding practice.

The bill bans cities and counties from using project labor agreements, which have been in use in the St. Louis area for decades. PLAs require all subcontractors to pay union wages, and often bar work stoppages over labor disagreements. Already, there are PLA bans on state projects.

Unions say such agreements guarantee a better-trained workforce and help construction projects meet deadlines. Opponents, including many Republicans, contend the agreements drive up costs and are unfair to nonunion businesses, with Greitens having called them “a sweetheart deal for special interests.”

“In the past, politicians across the state had entered into special deals with special interests, union bosses largely, to drive up the costs of construction projects,” Greitens said at the event in Earth City. “Well, here’s the problem. It’s not the politicians’ money. It’s your money.”

He added: “We need to be able to invest in infrastructure. Schools need to be fixed, courthouses need to be rebuilt, and libraries need to be repaired. But we should be paying a fair price. And in the past, too often, we weren’t.”

Republicans target PLAs in many states

More than 20 states have moved to ban project labor agreements, which had been in place in many states since the 1930s. Most of the bans have been enacted since 2010, including in Wisconsin, where Walker recently signed a similar bill. On the federal level, President Barack Obama signed an executive order in 2009 encouraging project labor agreements on federal projects, but business groups have been lobbying President Donald Trump and Congress to override it.

Walker, who made an unsuccessful bid for president in 2016 and now heads the Republican Governors Association, said banning PLAs is part of a national trend to help taxpayers and encourage economic growth.

“That’s what we’re talking about today, freedom and leveling the playing field,’’ Walker said.

Walker campaigned for Greitens last fall, a move that helped boost the new politician’s Republican credentials after a four-way primary during which he was accused of being a secret moderate.

After taking office in January, Greitens appeared to follow Walker’s playbook by swiftly focusing on ways to curb union clout. With a GOP majority in support, Greitens’ first bill-signing was to make Missouri a right-to-work state, barring employers and unions from requiring all workers to pay union dues or fees. (Walker did this in 2015, a law that was overturned by a state court, but later reinstated.)

Greitens expands focus to lawyers

Tuesday’s bill-signing is likely the last statewide anti-union measure to be signed this year, as several other related bills died during the General Assembly’s regular session, which ended May 12.

While he could call lawmakers back this summer to consider the failed measures, Greitens indicated Tuesday that he may wait until next session, which begins in January 2018.

“I think that there are number of reforms that we need to pursue,’’ Greitens said, adding that he plans to focus more on trial lawyers.

“We’re going to continue to push for labor and tort reform,’’ he said.

Greitens and Walker will be together again Wednesday at a meeting of the Republican Governors Association, which provided the bulk of Greitens’ campaign money — about $17 million — during his successful bid for governor against Democrat Chris Koster. Walker said his goal as RGA chairman was to continue to focus on electing other governors who share the same values as Greitens.